Many issues still surround the use of the Metric System in manufacturing today. In the 70's there was an effort to increase the use of the metric system in the United States. Congress passed the Metric Conversion Act of 1975, then the Omnibus Trade and Competitiveness Act in 1988, making the metric system the preferred method. Today the US still does not consider the metric system as its primary or preferred means of measurement.

Looking more specifically at the manufacturing of fasteners, screw, and bolts metric fasteners are in a large part driven by the Automotive Industry. Let's start with design and engineering. In the 70's many companies were still on draft boards, however today we fully utilize CAD systems which not only let us draw parts to size instead of scale, they easily switch between the english and metric systems of measurement. However specifications are still hard to get in metric, Why is there not a IFI standard for metric hex washer head when one is available in inches?